The following changes make it possible for Nuttx to load binaries in ELF format which are fully linked.
The change does not include the necessary modifications to produce such binaries. In order to build an applicable binary:
- The userspace applications linker script (`gnu-elf.ld`) needs to modified so the data and text section origin's match those setup by the address environment.
- The makefile used, in `apps/import/Make.defs` needs to remove the `-r` LDELFFLAG.
* include: Introduce elf64.h and elf.h
Added elf64.h for 64bit ELF support and moved common definitions
from elf32.h to elf.h. Also introduced Elf_xxx to be used in
common libraries such as binfmt.
* binfmt, include, modlib, module: Add support for ELF64
Elf_xxx must be used instead of Elf32_xxx to support ELF64.
To use ELF64, CONFIG_ELF_64BIT must be enabled.
* binfmt, modlib: Add support for relocate address
* arch: risc-v: Add include/elf.h
* libs: machine: Add risc-v related files.
NOTE: Currently only supports ELF64
* boards: maix-bit: Add elf and posix_spawn configurations
* boards: maix-bit: Add support for module configuration
